I have several NNs with pea comb and it really doesn't make a whole lotta difference in their heat tolerance. Body composition is much more important. My meatier NNs pant the most irrespective of comb or color.
Thank you for answering my question. I am more interested in the NN's that lay the eggs though, than the meat one's. I think that I would be better off going with the blue or green egg laying ones, as it would be easier for me to tell the difference between them in my incubators. Yes, I have 2 incubators now set to fire up for the spring hatches!